[codex] improve X article cover and Write button handling

[longhaiqwe]

Summary

• click the nearest clickable ancestor for the X Articles Write text node
• add a regression test for the Write button click expression
• document the generated X Article cover workflow, including 5:2 sizing and cover upload across Chrome plugin, Computer Use, and CDP modes

Why

X currently renders [data-testid="empty_state_button_text"] as an inner text node. Calling .click() on that node may not open the editor, so article publishing can stall on the drafts page even when the Write control is visible.

X Articles also recommends a 5:2 cover image. The skill now records the practical flow for generating a simple no-text cover, normalizing it to an exact ratio, verifying dimensions, and uploading it as the article cover rather than as a body image.

Validation

• bun test skills/baoyu-post-to-x/scripts/x-utils.test.ts skills/baoyu-post-to-x/scripts/md-to-html.test.ts skills/baoyu-post-to-x/scripts/x-article.test.ts
• bun skills/baoyu-post-to-x/scripts/x-article.ts --help
• git diff --check

[JimLiu]

Out of scope
这个不属于当前 Skill 功能范围